188 Syrphidae. 



rectangular. Squamulæ dirty whitish with a whitish or yellowish 

 frinc'e. Halteres yellow or brownish with the knob more or less black 

 to quite black. 



Female. Eyes very slightly hairy, practically bare. Frons some- 

 what narrow, widened downwards, with shallow and narrow side 

 channels and the middle channel indistinct or wanting; it is haired 

 with mixed pale and black hairs, sometimes ahiiost all pale or on 

 the contrary all black. Antennæ with the third joint larger and longer 

 than in the male. Thorax finely punctate, shining, clothed with short, 

 yellow, obliquely erect hairs among which some single black; scutellum 

 with six to eight long marginal bristles. Abdomen narrow, fmely 

 punctate, shining; it is clothed with short, black, depressed hairs, at 

 the sides with longer, erect, whitish hairs; fourth and fifth segments 

 quite black-haired, or only at the front corners of the fourth some 

 yellow hairs. Legs chiefly as in the male, hind femora not setulose 

 beneath. Halteres yellow. 



Length 6 to about 8 mm. 



This species may be known by its narrow shape, the characteri- 

 stic colour of the anterior tarsi and the bare or almost bare eyes in 

 the female, in both the latter respects resembling albitarsis, to which 

 it is certainly related. 



C. mutabilis is not rare in Denmark; Rørvig, Tisvilde, Nyraad 

 near Vordingborg; on Lolland at Nysted; on Langeland at Lohals; on 

 Funen and Middelfart, Odense and Hoffmansgave ; in Jutland in Greis- 

 dal and Højenbæk Dal at Vejle, at Horsens, Holstebro, Søndervig, 

 Sæby and Skagen, and on Bornholm at Rønne, Hasle and Allinge. 

 My dates are ^^/e — ^/s, it is thus a somewhat late species. It occurs 

 on fieids and meadows on flowers and in low herbage. 



Geographical distribution: — All Europe, towards the north to 

 northern Sweden, and in Finland. 



30. C. ruralis Meig. 



1822. Meig. Syst. Beschr. III, 293, 29 (Syrphus). — 1902. Beck. 

 Zeitschr. Hymn. Dipt. II, 354,29. — 1907. Kal.'palåarkt. Dipt. III, 37. — 

 Eristalis praecox Zett. 1843. Dipt. Scand. II, 801, 25 et 1855. XII, 4668, 

 25 et 1859. XIII, 6018, 25. — C. praecox 1862. Schin. F. A. I, 287. — 

 1894. Beck. iNov. Aet. Leop. Carol. Akad. LXII, 493, 126, Fig. 85. — 1901. 

 Verr. Brit. Fl. VIII, 251,22. — Syrphus urhanus Meig. p.p. 1822. 1. c. III, 

 287, 16. — C. urbana 1902. Beck. Zeitschr. Hymn. Dipt. Il, 352, 16. — 

 C.glabrata Meig. 1838. 1. c. VII. 125, 15. - 1902. Beck. 1. c. II, 355,15. 



Male. Somewhat narrow species. Eyes with short, pale yellowish 

 hairs. Frons somewhat small, gi-eyish pruinose, especially towards the 



